以丙烯酸为接枝单体, 二苯甲酮为光敏剂, 在紫外光的引发下对废胶粉进行表面接枝, 用正交方法对改性工艺进行了优化, 制备了改性废胶粉/天然橡胶复合材料, 表征了改性前后废胶粉的表面形貌和结构, 考察了其加入量对复合材料力学性能的影响。结果表明: 当丙烯酸和二苯甲酮与废胶粉的质量比分别为10%和9%, 废胶粉粒径为150 μm和光照时间为4 min时, 为最佳工艺条件, 此时接枝率最高, 达3.38%; 接枝改性后的废胶粉表面粗糙度增加; 随改性废胶粉含量的增加, 复合材料的拉伸强度和邵氏A硬度先增大后降低, 并在质量分数10%时达到最大值, 分别为27.28 MPa和69.2 HSA。

The surface of waste rubber powder (WRP) grafted with acrylic acid (AA) was performed under the inducing of ultraviolet (UV) using benzophenone (BP) as photosensitizer. The fabrication parameters were optimized via orthogonal method. The modified WRP/natural rubber (NR) composites were fabricated. The surface morphology and structures of WRP before and after modified, and the effects of WRP content on the mechanical properties of WRP/NR composites were studied. Results show that the highest grafting degree of 3.38% was gained in the optimized condition with 10wt% AA, 9wt% BP, 150 μm grain size of WRP and 4 min of illumination time. The rougher surface of modified WRP was observed when compared with the unmodified samples. The tensile strength and Shore A hardness were increased first, and then decreased with the content of modified WRP increased, and the peak values (27.28 MPa and 69.2 HSA, respectively) were obtained when 10wt% WRP added.